I encountered a strange behaviour of comparing values.  I've only encountered it with a value of "INF". The following script should cause "INF" to be displayed in version 3.0.18 on Linux

<?php
	$arr =array( 
	"TEST",
	"INF"
	);
	$cnt = sizeof($arr);
	for ($x=0; $x < $cnt; $x++) {
		$item = $arr[$x];
		if ("$item" == "$item") {
		} else {
			print "$item<br>\n";
		}
	}
?>